Cord anti-snag device



June 25, 1968 f c. SALMONSON 3,390,375

CORD ANTI-SNAG DEVICE Fild May 51, 1966 INVENTOR. CRAIG SALMONSON AGENT United States Patent 3,390,375 CORD ANTI-SNAG DEVICE Craig Salmonson, Castro Valley, Calif. (4404 Burke Way, Fremont, Calif. 94536) Filed May 31, 1966, Ser. No. 553,929 3 Claims. (Cl. 339-196) ABSTRACT OF THE DISCLOSURE A device for preventing an electrical cord from snagging, comprising a cone shaped member having a cavity therein and adapted to fit over a cord and against a cord connector, the device including a cord gripping means and a fastener means adapted to force the cord gripping means inwardly against the cord to secure the device to the cord and against the connector.

The present invention relates generally to electrical cord connector protector apparatus, and more particularly to a cord anti-snag device, which is demountably secured to an electrical cord adjacent the plugs or connectors thereof to prevent the plug from catching on, or otherwise becoming wedged in, cracks or corners of a structure when the cord is dragged along the ground or on the structure during construction thereof.

In the construction of structures various electrical apparatus such as saws, drills, paint sprayers, etc., are utilized, generally necessitating the use of a multiple number of electrical cords connected together. In the course of moving from one spot to another, the cord or cords are naturally dragged along the various portions of the structure and the connectors or plugs thereof tend to catch or snag in the many cracks, corners and/or crevises in the structure. This is particularly hazardous when walking across a roof of a single story building, or on the structure of a multiple story building, for when the cord plug snags the apparatus may be jerked from the workers hand and be damaged by the subsequent fall. Or worse, the worker himself could lose his balance and fall from the building. In any event, when a plug snags, the worker must return to the location of the snag to undo same which procedure is time consuming and very annoying to the worker. 7

Various devices have been devised which are attached to assembled male and female plugs to seal the assembled plugs from moisture and/or to lock the plugs together to prevent their being pulled apart during use. Typical of such devices are elongated cylindrical rubber devices having a continuous cavity therein for receiving both of the assembled plugs, and further having various complex and expensive zippers, tabs, rubber seals, or other similar moisture sealing features for completely enclosing the plugs. Such devices are expensive to fabricate, unwieldy to use, and provide such bulk and configuration as to enhance snagging of the cords when they are dragged, rather than alleviating the snag problem.

The present invention overcomes the above short-comings of prior art devices while alleviating the problem of snagging electrical cords when utilizing electrical equipment in the course of constructing a structure.

Accordingly, it is an object of the invention to provide an extremely simple, inexpensive, electrical cord antisnag device readily capable of mass production.

It is another object of the invention to provide an antisnag device which can be readily installed in seconds to either an electrical cord wherein the plugs are not yet assembled to the cord, or to an assembled electrical cord.

It is a further object of the invention to provide an anti-snag device which affords anti-snag protection to prevent the plugs from snagging when the cord is being 3,390,375 Patented June 25, 1968 dragged, but which allows immediate disassembly of coupled plugs without disassembling the anti-snag device.

Other objects and advantages will be apparent from the description taken together with the drawings, in which:

FIGURE 1 is a simplified cross-section view of a pair of anti-snag devices secured in place adjacent an assembled pair of plugs;

FIGURE 2 is a perspective cross-section view of an embodiment of the invention;

FIGURE 3 is a cross-section view of the embodiment of FIGURE 2 installed against a plug;

FIGURE 4 is a cross-section view of a modification of the embodiment of FIGURES 2 and 3;

FIGURE 5 is a perspective view of an alternative embodiment of the invention;

FIGURE 6 is a cross-section view taken along section line 66 of FIGURE 5;

FIGURE 7 is a partially broken-out perspective view of yet another embodiment of the invention; and

FIGURE 8 is a cross-section view taken long section line 8-8 of FIGURE 7.

Referring to FIGURE 1 there is depicted, in simplified form, a pair of anti-snag devices 10' secured to the ends of respective cords 12 adjacent to and against respective plugs 14. The devices 10 are provided with a cavity 16 at the largest end thereof whereby they may bear against the plug 14 while allowing space therein for the plug securing clamp 18 which is an integral part of most conventional industrial electrical plugs. The outside diameter of the larger end of the device 10 is made substantially equal to the diameter of the respective plug 14 near which it is secured, and the device is tapered in conical form to the smaller end which has an outside diameter just slightly larger than the cord 12 to which the device is secured. Thus, a smooth, comically-tapered surface is cord profile with no abrupt obstructions, such as the clamp 18 and/or the plug itself, which would tend to catch or otherwise snag upon corners and other portions of the structure being constructed.

Referring to FIGURE 2, there is shown in greater detail one embodiment 20 of the invention, comprising a cone-shaped member 22 preferably formed of plastic, nylon or other impact-absorbing, lightweight material. The member 22 is provided with the cavity 16 of previous mention along and within generally the half portion thereof terminating in the largest outside diameter, and an axially extending channel 24 is formed through the otherwise solid portion of the member 22 which terminates in the smallest outside diameter. The channel 24 has an inside diameter commensurate with the diameter of the cord 12' to which it is to be attached, e.g., slightly larger, such that the device 20 may be slipped over the cord and secured thereto. The inside circumferential surface of the channel 24 is machined to define stepped retaining grooves 28 therein. A pair of matching, demountable generally cylindrical inserts or cord clamps 30 is fitted circumjacently within the retaining grooves 28 formed in the cone-shaped member 22. The clamps 30 are formed preferably of metal, plastic or similar rigid, tough material. The solid portion of the cone-shaped member is drilled and threaded with opposing holes as at 32, in register with the retaining grooves 28 and cord clamps 30. Set screws 34 are disposed within the threaded holes 32 such that when tightened the ends thereof bear against the outer surface of the respective clamps 30 to urge same radially inward against the cord 12'.

In assembly, as shown in FIGURE 3 tightening the opposing set screws 34 forces the ends thereof against the outer circumference of the cord clamps 30 and urges them radially inward against the cord 12' disposed therethrough. The inside circumferential surfaces of the clamps 30 are preferably provided with a series of corrugations 35, or are otherwise scored or knurled, to provide a more positive biting action between the clamps 30 and the cords outer surface, which action holds the device firmly in place against the plug 14.

Since the clamps are free to move radially inward a selected distance the device 20 may be used with a cord 12' which has a diameter slightly smaller than the channel 24 of the device. However, if the cord diameter is substantially smaller and if a smaller size device is not available or desired, spacer inserts 36, shown in FIG- URE 4, may be disposed one at a time within the channel 24 of the device 20 in place of the clamps 30. The spacer inserts 36 are adapted to fit concentrically within the channel 24 with concentric stepped portions 37 which match and fit within the retaining grooves 28. The spacer inserts 36 protrude from the smaller diameter end of the cone-shaped member 22, and the protruding ends have an outer conical surface 38 which extends in coextensive conical relation to the outer conically-tapered surface of the member 22, thereby extending the comically-tapered surface thereof to a size commensurate with the smaller diameter cord to provide an anti-snag leading ledge which closely approaches the smaller cord circumference in the manner of the invention.

Accordingly, as may be seen, the clamps 30 in essence comprise a coextensive portion of the channel 24, which is moveable in a radially inward direction. Thus the clamps 30 (or the spacer inserts 36) comprise a cord gripping means integrally but translatably disposed within, and forming a continuation of, the channel 24. The set screws 34 threadably disposed in the holes 32 comprise a fastener means integrally formed within the member 22 and adapted to urge the clamps 30 or inserts 36 radially inward. Note in addition, only one clamp 30 or insert 36 and respective set screw 34 need be used to define the gripping means and fastener means respectively, wherein inward movement of the single clamp or insert will effect the gripping action against the cord 12'.

Additionally, the channel need not be grooved in the stepped fashion shown in FIGURES 2-4, but could have only a single step. In FIGURE 4, there need be no step at all; the insert could be an annular cylindrical member with a continuously smooth outer surface terminating in the outer conical surface 38.

FIGURES 5 and 6 depict an alternative embodiment 40 of the invention wherein the single cone-shaped member 22 is replaced by a cone-shaped member 42 which is split in half axially down the middle to form confronting, similar flat surfaces 43 along an axially extending plane passing through the device 40, wherein the member 42 is formed preferably of a plastic, nylon or like material. Thus, the device 40 can be secured to a cord which already is assembled to a plug without having to first remove the plug. A channel 44 is axially formed through the smaller diameter portion of the member 42, and has a series of corrugations 45 concentrically formed therewithin to provide a gripping action against the cord to which the device 40 is assembled. Each half of the member 42 is provided with at least one lock post 46 integrally formed on its respective, confronting flat surface 43 adjacent the channel 44, and a lock aperture 48 axially spaced from the lock post 46 at an equal distance from the channel 44 and further along the fiat surface 43. Thus the lock post 46 of each half is disposed in register opposite the respective lock aperture 48 of the other half. It may be seen that each half is an exact counterpart of all other halves and any two halves will form a pair, thereby requiring only one mold or die for fabricating the halves thus reducing the cost of manufacture of the embodiment 40. The device 40 may be manufactured in various sizes with different outside diameters as well as different channel diameters, as required to fit different size plugs and cords. In addition, cylindrical annular spacer inserts (not shown) such as the spacer inserts 36 of FIGURE 3, but without the stepped portions 37, may be utilized to adapt a device 40 having a large diameter channel 44, to one having a smaller diameter channel for use with a smaller diameter cord.

Accordingly, it may be seen that in the embodiment 40 of FIGURES 5-6, the cord gripping means in essence comprises at least a portion of the channel walls them selves, wherein radially inward movement of the cord gripping means is effected upon assembling the two halves of the conical member 42 together. The fastener means in this embodiment thus comprises a mating lock means defined by the combination of the lock posts 46 and the respective lock apertures 43 of opposite halves.

Referring to FIGURES 7 and 8, a further alternative embodiment 50 of the invention comprises a conical member 52 formed preferably of a somewhat flexible, but hard, rubber such as is used to form plugs for extension cords. A channel 54 is coaxially formed in the otherwise solid portion of the member 52, with the inside surface thereof having concentric grooves or serrations 56 formed therein. An axially extending slot 58 is formed along a plane passing through the axis of the member 52, the slot 58 extending completely through the member from the axis out to one outer conical surface, and partially into the solid portion diametrically opposite thereto. Thus the device 50 can be Spread apart along the slot 58 to allow it to be slipped over an assembled cord (not shown) and into position adjacent the plug thereof. The solid portion of the member 52 has a hole 60 transversely drilled therethrough generally perpendicular to the slot 58, and a bolt 62 disposed therein. The head and nut of the bolt 62 are countersunk within the hole 60 as at 63, to provide a smooth conical outer surface. Tightening bolt 62 presses the halves of the slotted member 52 together to urge the serrations 56 firmly against the outer surface of the cord (not shown) disposed in the channel 54, thus firmly clamping the device 50 to the cord.

As discussed previously, the embodiment 50 having a large channel 54 may also be provided with a spacer insert (not shown) which would fit over a smaller cord and within the channel 54. The spacer insert may be formed of an annular cylinder axially slotted along one wall, whereby it may be spread apart to fit over the cord, and then slid along the cord and into the channel of the device 50. Tightening the bolt 62 then confines the spacer insert between the channel wall and the cord to firmly secure the device 50 to the cord.

Accordingly, in the embodiment 50 the channel 54 and slot 58 provide the cord gripping means of the invention, and the bolt 62 comprises the fastener means of previous mention.

Although various embodiments of the invention have been particularly described herein, it is to be understood that various modifications thereto and further embodiments thereof may be made within the spirit of the invention. For example, the angle of the comically-tapered outer surface may be varied through a selected range, the various channels may or may not be provided with the serrations, and the internal cavities may be of any suitable shape and configuration to allow assembly of the various devices against their respective plugs. Also the channels may be other than circular in shape, e.g., oval or even square. The ratio of the outer diameters and the channel diameters likewise may vary, dependent upon the size of the plug and cord which are or will be assembled together. Thus it is not intended to limit the scope of the invention except as defined in the following claims.

What is claimed is:

1. An anti-snag device for installation on electrical cords adjacent to the plugs for preventing the cords from snagging on obstructions when being dragged, the device comprising;

a truncated conical member having a coaxial channel formed therethrough, said member and channel being adapted to grip said cord;

said truncated conical member terminating in small and large diameter ends, said member further having a cavity formed within the larger diameter end with one end of the channel in communication with the cavity;

said larger diameter end of said member being adapted to abut in coextensive relation the outside diameter of the adjacent plug, the smaller diameter end of the member having an outside diameter slightly greater than the diameter of the cord to which it is secured;

cord-gripping means disposed within the conical member and radially translatable therein for providing a cord gripping surface and action, said cord-gripping means being formed of a radially translatable portion of the channel walls, wherein movement of said portion of said cord-gripping means effects said cordgripping action;

said cord-gripping means being further defined by said channel having a stepped groove formed circumja cently within the wall thereof, and clamp means defining said radially translatable portion fitted within said stepped groove and having a cord-gripping inside surface; and

fastener means disposed within said conical member for urging the cord-gripping means against the cord surface to secure the device thereto against said plug, said fastener means being adapted to effect said radially inward movement of said portion;

said fastener means including a set screw threadably disposed within the conical member with the end thereof bearing against the clamp means, whereupon tightening said set screw urges said clamp means against the cord to secure the device thereto.

2. An anti-snag device for installation on electrical cords adjacent to the plugs for preventing the cords from snagging on obstructions when being dragged, the device comprising;

a truncated conical member having a coaxial channel formed therethrough, said member and channel being adapted to grip said cord;

said truncated conical member terminating in small and large diameter ends, said member further having a cavity formed within the larger diameter end with one end of the channel in communication with the cavity;

said larger diameter end of said member being adapted to abut in coextensive relation the outside diameter of the adjacent plug, the smaller diameter end of the member having an outside diameter slightly greater than the diameter of the cord to which it is secured;

cord-gripping means disposed within the conical member and radially translatable therein for providing a cord-gripping surface and action, said cord-gripping means being formed of a radially translatable portion of the channel walls, wherein movement of said portion of said cord-gripping means effects said cordgripping action;

said cord-gripping means further being formed of a substantial portion of the inside circumferential surface of the channel which defines thus the radially translatable portion, said conical member further having an axially-extending slot formed therethrough; and

fastener means disposed within said conical member for urging the cord-gripping means against the cord surface to secure the device thereto against said plug, said fastener means being adapted to effect said radially inward movement of said portion;

said fastener means further including a lock bolt disposed within the conical member and transversely spanning the axially-extending slot, wherein tightening said lock bolt urges the walls of the slot together to press the substantial portion of the channel surface radially inwardly against the cord to secure the device thereto.

3. An anti-snag device for installation on electrical cords adjacent to the plugs for preventing the cords from snagging on obstructions when being dragged, the device comprising;

a truncated conical member having a coaxial channel formed therethrough, said member and channel being adapted to grip said cord;

said truncated conical member terminating in small and large diameter ends, said member further having a cavity formed Within the larger diameter end with one end of the channel in communication with the cavity;

said larger diameter end of said member being adapted to abut in coextensive relation the outside diameter of the adjacent plug, the smaller diameter end of the member having an outside diameter slightly greater than the diameter of the cord to which it is secured;

cord-gripping means disposed within the conical member and radially translatable therein for providing a cord-gripping surface and action, said cord-gripping means being formed of a radially translatable portion of the channel walls, wherein movement of said portion of said cord-gripping means effects said cordgripping action;

fastener means disposed within said conical member for urging the cord-gripping means against the cord surface to secure the device thereto against said plug, said fastener means being adapted to effect said radially inward movement of said portion; and

an elongated annular spacer insert concentrically disposed within the channel of the conical member and having a channel formed therein of a diameter smaller than the diameter of the confining channel of the conical member, said unnular spacer insert extending from the smaller diameter end of the conical member and having a truncated conical outer surface substantially matching and coextensively extending the conical outer surface of the smaller diameter end of the truncated conical member.

References Cited UNITED STATES PATENTS 2,043,666 6/1936 Kingsbury 33963 2,097,057 10/1937 Brown 339-63 3,014,194 12/1961 Berglund 339- 3,316,523 4/1967 Trangmar 339-101X FOREIGN PATENTS 628,786 10/1961 Canada. 863,386 3/1961 Great Britain.

RICHARD E. MOORE, Primary Examiner. 

